Method and device for lining a well using hydroforming

ABSTRACT

The present invention relates in particular to a lining process for a line (C) using hydroforming of a liner ( 3 ), according to which: a) a tool ( 1 ) is inserted axially into said liner ( 3 ) whereon are mounted two radially expandable plugs ( 2 ); said tool ( 1 ) is positioned inside the liner ( 3 ) so that the plugs ( 2 ) are located facing its end portions ( 33 ); the plugs ( 2 ) are slightly expanded so as to bind the tool ( 1 ) to said liner ( 3 ); the assembly consisting of the tool ( 1 ) and the liner ( 3 ) is inserted axially into the well or the line (C); fluid under pressure is sent into the liner ( 3 ), between the two plugs ( 2 ) so as to cause radial expansion of only the central portion of the liner ( 3 ); eventually, said plugs ( 2 ) are again expanded with sufficient pressure for them to cause radial expansion of the two end portion ( 33 ) of the liner ( 3 ), applying them against the inner wall (Cp) of the line (C); said plugs ( 2 ) are retracted and the tool ( 1 ) is withdrawn from the line (C), characterized by the fact that retraction of said plugs ( 2 ) is carried out by generating a vacuum inside them.

The present invention relates to a method and a device for lining a well or a line, a casing for example, having a portion to be treated, particularly to be repaired and/or plugged.

The invention applies more particularly but not obligatorily to the field of water or petroleum production.

In the description that follows the invention will be described, by way of example, in the field of petroleum production.

A casing is a metal tube which lines the interior of a petroleum well over a considerable length.

In the course of time, it happens that a portion of the wall of the casing needs to be sealed, particularly when it is deteriorated, for example by wear and/or cracking, or when the perforations designed for the passage of petroleum must be plugged, in particular because the deposit is exhausted in this area and undesirable fluid products (water and gases in particular) threaten to pass through the wall of the casing and penetrate inside it.

Different technologies, which employ plastically expanded metal liners made of ductile steel, have been proposed.

A first method consists of directly applying radial pressure to the metal liner to expand it. To that end, a cone-shaped tool can be used which is moved longitudinally along the metal sleeve.

Examples of such a technique are described for example in the following American patents: U.S. Pat. Nos. 7,191,841, 7,216,701, 7,270,188 and 7,350,564.

By using such a technique, it is possible to deform great lengths of liner by butting together unit lengths of about 12 m each for example.

However, the diameter of the expanded liner is dependent on the diameter of the cone and may not conform to the diameter of the formation to be repaired.

Furthermore, the expansion of the sleeve occurring generally from the top toward the bottom of the well, it is necessary to recover the cone after the end of the operation, which is tedious. When that is difficult or impossible, it is left in place and it is drilled through, so that the well fluids circulate freely through it.

Furthermore, in certain situations, problems are encountered in freeing the well in the event of jamming of the cone during the expansion, this jamming possibly being due, for example, to a local collapse of the wall to be treated.

Another technique consists of using a tubular liner or metal “patch” which is expanded using a cylindrical tool which can be moved axially within the patch.

Such a technology is described for example in document FR A 2 934 634 of the present Applicant.

Such a technology is practical because the expandable tubular liner conforms to the diameter of the formation. Furthermore, due to the use of a cylindrical expansion tool, there is little or no risk of having it become jammed during the expansion phase.

However, the expansion is performed stepwise, by moving the expansion tool longitudinally, so that the time required to treat the total length of a very long liner is considerable.

Yet another technology consists of exerting radial pressure on the body of the tube to be expanded, by hydroforming.

Reference can be made in particular to document FR A 2 901 837, also in the name of the present Applicant, wherein use is made of this hydroforming technique.

The pressure is exerted by a fluid directly on the inside of the liner to be expanded and use is made of two sealing tools at opposite ends of the liner.

Such a solution is of interest because expansion takes place in one step by pressurization of the inside of the liner and elastic deformation, simultaneous or deferred, of the sealing tools.

Great lengths of liner can be treated by butting together unit lengths of about 12 m each.

Furthermore, the final diameter of the expanded liner does not depend on an expansion tool, but on the application of a predetermined pressure. Finally, the expanded liner conforms to the diameter of the formation or is limited to the diameter given by the hydroforming pressure.

One of the difficulties that are encountered with this type of technique concerns the seal between the liner and the sealing tools or plugs.

Indeed, as the liner deforms radially during its expansion, it is necessary to deform in like fashion the sealing tool while still maintaining sufficient contact pressure between the liner and the tool to maintain the hydroforming pressure within the liner.

This technique, which is complicated to implement, requires complicated and fragile expansion tools which, in addition, do not allow circulation of fluid while the installation tool is being lowered.

Finally, it is necessary to maintain pressure in the sealing tools if they are expected to support the liner by contact pressure while being lowered into the well.

The present invention has as its object to correct these difficulties and to propose a lining method using hydroforming as well as a corresponding device which makes it possible to maintain the liner during lowering into the well without it being necessary to maintain pressure in the installation tool, while still allowing circulation within the well so as maintain control of it.

Another object is to allow the installation tool to be freed at the end of the operation, by using means that are simple and practical to implement.

Thus, a first aspect of the invention relates to a lining method for a well or a line, a casing for example, having a portion to be treated, particularly to be repaired and/or plugged, by hydroforming of a tubular metal liner the initial diameter whereof is substantially smaller than that of the well or of the line and the end portions whereof are mechanically reinforced, according to which:

a) a tool is inserted axially inside this sleeve, the tool including a mandrel on which are mounted two plugs that are radially expandable under the influence of an internal hydraulic pressure, these two plugs being axially separated from one another, by a distance that is substantially equal to, or slightly smaller than the length of the liner;

b) said tool is positioned inside the liner so that the plugs are situated facing its end portions;

c) the plugs are slightly expanded so as to bind the tool, by friction, to said sleeve without noticeably deforming the liner;

d) the assembly consisting of the tool and the liner is inserted axially into the well or the line, and it is positioned facing the area to be lined;

e) eventually, fluid is introduced under pressure into the liner, between the two plugs, so as to also cause radial expansion, by hydroforming, of only the central portion of the liner, located between the two end portions;

f) said plugs are again expanded with sufficient pressure to make them cause radial expansion of the two end portions of the sleeve, applying them fluid-tight against the inner wall of the well or of the line;

g) said plugs are retracted, and the tool is withdrawn from the well or the line,

characterized by the fact that the plug expansion steps are carried out by plastically deforming them and that, during step g), retraction of these plugs is accomplished by generating a vacuum inside them.

Thus, due to the plastic deformation of the plugs, it is not necessary to maintain a high pressure inside them. Moreover, despite this plastic deformation which is, a priori, permanent, it is nevertheless possible to easily extract said plugs by generating a vacuum inside them.

According to advantageous and preferred features, taken separately or in any combination:

-   -   plugs with plastically deformable metal walls are used, so that         in step g) said generation of a vacuum causes their wall to         collapse;     -   a mandrel is used having a single pipe for circulating a liquid         under pressure, which communicates through openings with said         plugs and the central portion of the liner, respectively;     -   implementation of step e) is dispensed with;     -   during expansion of said plugs, closure of the communication         openings between said pipe and the central portion of the liner         is carried out.

Another aspect of the invention relates to a device for lining a well or a line, a casing for example, having a portion to be treated, particularly to be repaired and/or plugged, by hydroforming a tubular metal liner the initial diameter whereof is substantially smaller than that of the well or the line, which comprises:

-   -   a tool capable of being inserted axially into the inside of the         liner, said tool having a mandrel whereon are mounted two plugs         that are radially expandable under the influence of an internal         hydraulic pressure, these two plugs having, in an initial state,         a diameter less than or equal to the inner diameter of the         liner, and being axially separated from one another by a         distance substantially equal to, or slightly less than the         length of the liner, said tool being adapted to be positioned         within the liner so that the plugs are located facing its end         portions;     -   hydraulic means for, on the one hand, expanding said plugs at a         pressure high enough for them to cause the radial expansion of         the two end portion of the liner, applying them fluid-tight         against the inner wall of the well or of the line, after         insertion of the assembly consisting of the tool and the liner         into the well or the line and positioning said assembly opposite         the area to be lined and, on the other hand, to expand the         middle portion of the liner located between said plugs,

characterized by the fact that said tool comprises a single pipe for circulating a liquid under pressure, which communicates, through openings, with said plugs and the central portion of the liner, respectively, and that said plugs are plugs capable of being plastically deformed.

According to advantageous and non-limiting features of this device:

-   -   said pipe leads, through an opening, to the distal end of said         tool and it comprises an external valve for closing said         opening, which is capable of opening once the pressure inside         the tool is greater than the pressure outside;     -   said tool comprises, inside said pipe, a sliding liner capable         of covering or opening, respectively, said openings         communicating with the central portion of the liner;     -   it comprises a plug designed to be movable at will within the         pipe capable of applying itself against said opening, at the         distal end of said tool, to close it;     -   it comprises a generally cylindrical movable member, which in a         resting position bears against said plug and which, in a first         working position is capable of displacing said sliding liner to         cover said communication openings of said pipe with the central         portion of the liner;     -   said movable member is slightly deformable and shaped in such a         way that it is able to pass through said sliding liner after         having moved it;     -   said pipe comprises in its upstream portion, located above the         associated plug, a cross-section restriction;     -   said movable member is shaped so that it can be inserted into         said cross-section restriction and seal it; and     -   said movable member comprises a peripheral sealing lip.

Other features and advantages of the present invention will appear upon reading the detailed description of certain preferred embodiments.

This description is made with reference to the appended drawings wherein:

FIG. 1 is a longitudinal section view of a lining device conforming to the invention, placed inside a tubular metal liner and shown in an initial, non-deformed state;

FIG. 2 is a view similar to FIG. 1 wherein plugs have been partially deformed and solely so that the tool can be placed in frictional contact against the liner to be expanded;

FIGS. 1A and 2A are half-views corresponding to FIGS. 1 and 2 placed side by side and designed to illustrate well the different states of the device;

FIG. 3 is a partial longitudinal section view of a liner, at one of its mechanically reinforced end portions;

FIG. 4 is a view similar to FIG. 2, which shows the state of the device according to the invention and the associated liner during lowering of this assembly into a well;

FIGS. 5A and 5B are half longitudinal section views of two more states of the device according to the invention which correspond to two steps in implementing the method;

finally, FIGS. 6A and 6B are similar half-views showing the device at the end of the process, before and after the withdrawal of the toll from the deformed liner.

The detailed description of the device according to the invention is given essentially with reference to FIGS. 1, 2, 1A and 2A, wherein it is assumed that the tool 1 shown in these figures is not yet inserted into the well to be treated.

The aforementioned tool 1 consists essentially of a cylindrical metal mandrel through which runs, along its longitudinal axis X-X′, a single pipe 16. The upper part of the tool is attached to a positioning member such as drill string, continuous coiled tubing 7 or a liner.

The pipe 16 runs through it end to end. It exhibits in its downstream portion, located in the lower half of the figures, a relatively large nominal diameter 16′, while the upstream portion (located toward the surface of the well), comprises a much reduced cross-section, labeled 16″.

A truncated transition zone connects the two and is labeled 160 in the figures.

The downstream portion of the pipe 16, having nominal diameter 16′, communicates with the outside through three series of through openings 14 and 15.

The openings 14 are located not far from the opposite ends of the portion of pipe having diameter 16′, while the openings 15 are located substantially halfway between the opposite ends.

Inside the pipe 16, in the aforementioned downstream portion, is a sliding cylindrical and annular liner 13 capable of covering or uncovering respectively the aforementioned openings 15.

Its displacement is accomplished by sliding the liner by means of the plugs which will be described later.

This liner is held in place in its extreme positions, for example by a system of thrust rings or retractable pawls (known per se and not shown).

Of course, due to its annular shape, the liner can allow passage by a liquid which would be introduced into the pipe 16.

The distal end of the tool, which forms an opening 110, communicates with the pipe 16 via a truncated transition zone 11 which, as will be seen later, constitutes a seat for a closing plug.

The opening 110 is provided with an outside shutoff valve 4 which is capable of opening when the pressure inside the tool 1 is greater than the outside pressure and, conversely, positions itself in the closure position (as shown in FIG. 1) whenever the pressure inside the tool is lower than the pressure outside.

A pair of plugs labeled 2 is attached to the outer wall of the mandrel 1. Each plug consists of two non-deformable annular rings 22, fixed to the wall of the mandrel, the two rings being connected by a thin cylindrical wall 21 made of ductile metal such as steel, said wall defining with the two associated rings an inner space E which communicates with each of the aforementioned series of openings 14.

As will be seen later, the wall 21 is capable of deforming plastically, in other words beyond the elastic recovery limit of the material constituting it.

The same mandrel as before is shown in FIG. 2, within which is positioned a tool 5 and the end whereof is present a plug 51 the lower end whereof is so shaped as to be able to position itself against the seat 11 of the opening 110 located downstream of the mandrel.

This plug assumes a generally cylindrical shape and its diameter is such that it can be inserted by the upstream end of the mandrel via the pipe 16.

It will be noted, moreover, that this tool 5 is capable of accommodating another, sliding over the first, which bears at its distal end a generally cylindrical movable member 52 (see FIGS. 5A and 5B). This member 52 is preferably made of an elastically deformable material, and it exhibits in its upper portion a peripheral sealing lip 520 which, when no force is present, is deployed outward and then exhibits a nominal diameter greater than that of the member 52 properly so called.

The nominal diameter of this body is slightly less than the diameter of the opening in the liner 13 and also slightly less than the diameter of the pipe 16, in its zone having reduced diameter 16″.

The device, as it is shown in FIG. 1, is placed inside a liner that is intended to be positioned inside a casing to repair and/or plug it.

Said cylindrical liner 3 exhibits, in the absence of radial deformation, a diameter that is slightly larger than the diameter of the plugs 2 so that the tool 1 can be slipped inside it.

Its total length is slightly less than the separation between the opposite ends of the two plugs 2.

The intermediate central zone of the liner 3 is labeled 31 while its end parts (or end portions) are labeled 33.

The last mentioned are mechanically reinforced which means that they have the ability to deform less than the rest of the liner 3, under the influence of the same pressure.

To this end and as illustrated in FIG. 3, the end portions 33 can accommodate, on their outer surface, a sleeve M which increases (doubles, for example) their thickness. Inserted end portions, made of a different metal and having a higher elastic limit, can also be used, and welded for example to the rest of the liner 3. Strictly speaking, there is no noticeable excess thickness in this case.

For the sake of clarity in the figures, and with the exception of FIG. 3, the portions 33 have been shown without noticeable excess thickness.

In known fashion, at the end portions, the outer wall of the liner 3 accommodates an elastomer coating labeled 32.

We will now describe the implementation of the method of the present invention, first with reference to FIGS. 1 and 2 which, as already stated above, are preferably implemented before the insertion of the lining device inside a well or a casing.

The first step in the method according to the invention consists of inserting the aforementioned tool 1 inside the liner 3, and the following operation consists of positioning the tool so as to cause it to adopt the position of FIG. 1, that is the position wherein the plugs 2 are located substantially opposite its end portions 33.

The tool 5 is then positioned longitudinally within the pipe 16, so that the plug 51 comes to rest on the seat 11 of the distal opening 110.

Thus, the pipe 16 is plugged and the liner 13 covers the communication openings 15.

Fluid pressure is then applied inside the pipe 16, the pressure being sufficient to cause a slight plastic expansion of the wall 21 of the plugs 2 so that it becomes joined, by friction, to the liner 3, without noticeably deforming the liner.

The situation of FIG. 2 then exists, wherein said liner is joined to the tool via the plugs 2.

The tool 5 (and hence the plug 51) is then withdrawn. The liner 13 is then moved, using a tool that is not shown, so as to uncover the openings 15.

It is then possible to lower the assembly of tools 1 and 3 into the well or the line to position it facing the area to be treated, labeled C in FIG. 3 and subsequent figures. Of course, the mean diameter of this line is greater than the diameter of the liner 3 in its unexpanded position of FIG. 2.

The state assumed by the assembly during this descent is shown in FIG. 4. The openings 15 are uncovered. The inside of the pipe 16 is at the same pressure as the outside.

Preferably, the valve 4 will have been opened to allow circulation of liquid through the assembly.

In a subsequent step, the tool 5 is lowered into the positioning member, then into the tool 1 by means of a cable for example. The tool 5 is equipped with the plugs 51 and the member 52, so that they run through the sliding tubular liner 3 and position themselves over the opening 110. Thus, the downstream end of the mandrel is closed.

Opening the openings 15 therefore causes the middle portion of the liner 3 to communicate with the inside of the tool 1.

Hydroforming fluid pressure is then applied to the inside of the tool so that the liner 3 deforms essentially in its middle portion so as to press itself against the wall Cp of the line. The pressure applied is on the order of 200 to 250 bars for example.

Once this deformation is carried out, the pressure level can be brought back to zero.

Displacement of the movable member 52 is undertaken next by operating the rod to which it is connected which leaving the plug 51 in position.

In so doing, the member 52 displaces the liner 13 in the direction closing the openings 15, its lip 520 contributing to that displacement.

In the following step, the plugs 2 are again expanded with a greater pressure that is sufficient to cause the radial and plastic expansion of the two end portions 33 of the liner, applying them fluid-tight against the inner wall Cp of the line C.

The presence of an elastomer coating 32 makes it possible to perfect the fluid-tightness.

The situation of FIG. 5B then exists, wherein the line is perfectly lined.

After this operation, it is possible to “re-open” the openings 15 by displacement of the plug 51 and the member 52 to “re-inflate” the central portion of the liner 3 so as to ensure that the bond between it and the wall Cp is good.

It is then necessary to proceed with withdrawal of the tool 1 and of its associated plugs.

To this end, sliding of the plug 51 and of the movable member from downstream to upstream is carried out, by pulling on the rod 5.

The valve 4 then closes.

When the movable member 52 arrives in the portion of the pipe 16 having a reduced diameter 16″, its peripheral lip 520 retracts radially inward and said movable member then serves as a fluid-tight plug which makes it possible to generate a relative vacuum within the pipe compared to the outside pressure, within the well, on the order of 100 bars for example.

This vacuum is sufficient to cause the retraction of the plugs 2 and more precisely the collapse of their plastically deformed wall 21, which returns to an initial non-deformed state, or at least partially to a state wherein the space E is reduced relative to its initial state.

In a sense, a collapse of this wall is observed (FIG. 6A).

Thus, simply by generating a vacuum inside the pipe, it is possible to easily unbind the plugs 2 from the liner 3 and allow the withdrawal of the tool (FIG. 6B).

This is accomplished using a single pipe for the hydroforming fluid, which greatly simplifies the architecture of the assembly.

If this collapsing operation is not accomplished upon its first implementation, the movable member 52 is then moved from downstream to upstream and back so as to cause a kind of “pumping” which enables an improvement in the effectiveness of the vacuum inside the pipe.

Of course and if necessary, expansion of the central portion of the liner 3 can be dispensed with if only a localized sealing effect is desired.

The plugs are advantageously designed to be easily disassembled and replaced by others, as the collapse of their wall makes them ineligible for re-use. 

1. A method for lining a well or a line, a casing for example, exhibiting a portion to be treated, particularly to be repaired and/or plugged, by hydroforming a tubular metal liner, the initial diameter whereof is substantially less than that of the well or of the line, and the end portions whereof are mechanically reinforced, according to which: a) a tool is inserted axially into said liner, comprising a mandrel whereon are mounted two plugs that are radially expandable under the influence of an internal hydraulic pressure, said two plugs being axially separated from one another by a distance that is substantially equal to or slightly less than the length of the liner; b) said tool is positioned within the liner so that the plugs are facing its end portions; c) the plugs are slightly expanded so as to bind the tool, by friction, to said liner without noticeably deforming it; d) the assembly consisting of the tool and the liner is inserted axially into the well or the line, and positioned facing the zone to be lined; e) eventually, fluid under pressure is sent inside the liner between the two plugs, so as to also bring about radial expansion, by hydroforming, of only the central portion of the liner located between the two end portions; f) said plugs are again expanded with enough pressure to cause the radial expansion of the two end portions of the liner, applying them fluid-tight against the inner wall of the well or of the line; g) said plugs are retracted and the tool is withdrawn from the well or from the line, wherein the plug expansion steps are accomplished by their plastic deformation and wherein, during step g), retraction of said plugs is undertaken by generating a vacuum inside them.
 2. The method according to claim 1, wherein plugs are used having a plastically deformable metal wall, so that in step g), said generation of the vacuum causes collapse of their wall.
 3. The method according to one of claim 1, wherein a mandrel is used having a single pipe for circulating a fluid under pressure, which communicates respectively, through openings, with said plugs and the central portion of the liner.
 4. The method according to claim 3, wherein, during expansion of said plugs, closure of the communication openings between said pipe and the central portion of the liner is undertaken.
 5. The method according to claim 1, wherein the implementation of step e) is dispensed with.
 6. A device for lining a well or a line, a casing for example, exhibiting a portion to be treated, particularly by repairing and/or plugging it, by hydroforming a tubular metal liner the initial diameter whereof is substantially smaller than that of the well or of the line, which comprises: a tool capable of being inserted axially into the inside of the liner, said tool having a mandrel whereon are mounted two plugs that are radially expandable under the influence of an internal hydraulic pressure, these two plugs having, in an initial state, a diameter less than or equal to the inner diameter of the liner, and being axially separated from one another by a distance substantially equal to, or slightly less than the length of the liner, said tool being adapted to be positioned within the liner so that the plugs are located facing its end portions; hydraulic means for, on the one hand, expanding said plugs at a sufficient pressure that they cause the radial expansion of the two end portions of the liner, applying them fluid-tight against the inner wall of the well or the line, after insertion of the assembly consisting of the tool and the liner into the well or the line and positioning said assembly facing the zone to be lined and, on the other hand, expanding the middle part of the liner located between said plugs, wherein said tool comprises a single pipe for circulating fluid under pressure which communicates respectively, through openings, with said plugs and the central portion of the liner, and that said plugs are plugs capable of being plastically deformed.
 7. The device according to claim 6, wherein said pipe leads, through an opening to the distal end of said tool, and that it comprises an outside valve, closing said opening, which is capable of opening if the pressure inside the tool is greater than the outside pressure.
 8. The device according to claim 6, wherein said tool comprises, inside said pipe, a sliding liner capable of closing or opening respectively said openings communicating with the central portion of the liner.
 9. The device according to claim 6, wherein it comprises a plug designed to be movable at will within the pipe and capable of applying itself against said opening, at the distal end of said tool, to close it.
 10. The device according to claim 8 which comprises a plug designed to be movable at will within the pipe and capable of applying itself against said opening, at the distal end of said tool, to close it wherein it comprises a generally cylindrical movable member which, in a rest position, presses on said plug and which, in a first working position, is capable of displacing said sliding liner to cover said openings communicating between said pipe and the central portion of the liner.
 11. The device according to claim 10, wherein said movable member is slightly deformable and shaped so as to be able to pass through said sliding liner after having displaced it.
 12. The device according to claim 10, wherein said pipe comprises in its upstream portion, located above the associated plug, a cross-section restriction.
 13. The device according to claim 12, wherein said movable member is shaped so that it can be inserted into said cross-section restriction and seal it.
 14. The device according to claim 13, wherein said movable member comprises a peripheral sealing lip. 